This invention relates to a bonnet structure for use in sound-proof generators.
There has heretofore been known a sound-proof generator in which a cooling air intake is provided on one side of its bonnet, a generator and an engine for driving it are accommodated in the same chamber, and a radiator is fitted to its partition wall.
In the generator of such type, cooling air is introduced in it by rotating the generator's rotor-fan and the engine's fan so as to allow the cooling air to flow through the inside and outside of the generator and the outside of the engine and discharge the air warmed thereby through the radiator outside the engine.
Because of the engine and the generator being accommodated in the same chamber without a partition wall therebetween, such type of structure requires provision of a large area or space in which sound absorption material is installed. Further, passage of exhaust air from the generator kept at a comparatively high temperature through the radiator requires provision of a radiator having a large capacity.
In the above-mentioned bonnet structure, the inside and outside of the generator are cooled by cooling air; however, as a matter of fact, there is no need of cooling both the inside and outside of the generator, because the quantity of heat generated by the generator is limited or low.